External oil pressure regulator?

[bigaaron]

Anal isn't the word I'd use. Tribology principles don't change between a 250 and a 500 hp engine. I'd like to hear from an engineering standpoint exactly how higher oil pressure would be beneficial. I already know but I'd still like to hear it

If you have anything to add to the thread from an engineering standpoint then please do, but condescending rhetorical questions are not much help to anyone.

 

[jetjock]

Mo is betta! Close off the system, dead head the pump. Bleed a little off to avoid bustin' something. That should work

 

[jetjock]

Oh settle down Aaron. We're just playin'. I could add quite a bit but experience has shown you're resistant to change. If you think this is a good thing (like thick oil) then go for it. As long as you don't do it on my car I couldn't care less.

 

[bigaaron]

I'm not completely resistant to change, and I'm not the sharpest tool in the shed. I have not changed much of the oiling system on anyone's car other then adding a bigger cooler and a full flow t-stat, and shimming the pump on one engine after many people had good success with it.
I'm just in the process of building a new engine for myself and I want to test out any "upgrades" using my own car as the guinea pig.
Oh, and fyi we are using 10-40 instead of 20-50 now after listening to you guys rant about oil for the last year LOL

 

[jetjock]

Down to 10-40 huh? I don't believe it. Who says miracles don't happen?

You need some pressure otherwise there can be no flow. However the longer oil stays in a cyclically loaded journal bearing operating with a hydrodynamic wedge the closer it comes to being destroyed by the heat and forces involved. It needs to be replaced often enough to prevent that from happening. I'm simplifying things a bit but you get the idea. It's a balance. Not to mention the cooling aspects good flow provides. Then there's cold starting. Flow is also important then. As long as the viscosity is correct for the condition I'll take flow over pressure any day.

 

[IJ.]

I'm not against innovation as such it just bothers me when people are trying to fix a non existant problem.

The 7M oiling system is pretty stout as is and with a few minor changes is quite bullet proof.

It bothers me in threads like the sticky on solving the 7M's oil system issues things are being posted with no basis in fact and based on someone gut feelings that there is an issue with no supporting evidence.

The kids then read it and the latest Chi Chi becomes a must have, selling chi chi's isn't a problem as long as people understand that's what they're buying. (ie: those idiotic strut bars)

I hope this doesn't come across as harsh as I don't wish to offend anyone and have held my tongue since I've been back here.

 

[bigaaron]

This idea just came up by accident, so I figured I would put it out there and see what everybody thought about it. It seems like maybe it's a little overkill after all the input so far. The original plan was to use ARZ's hardpipe, go out of the block with -10 to a remote filter where mine already is, and then a full flow thermostat, then to an oil cooler, possibly with thermostatically controlled fan.

So to you engineer types, what is the optimum oil pressure for a high hp 7m?

 

[IJ.]

10 psi per 1000 rpm works for me.

 

[jetjock]

Generally speaking you should use whatever oil gives 10-12 psi per 1000 rpm with a hot viscosity of 10-12 centistokes. As the engine wears the viscosity will need to be changed. In high power applications an oil with a good boundary additive package should be used as it'll be the last line of defense should hydrodynamic lubrication fail. I'd use something with moly or boron.

edit: Dammit. Where women glow and men plunder

 

[johnathan1]

Can you hear, can you hear the thunder?

 

[jdub]

Got in a bit late on this one

Pressure will incease flow, but only to the point the oil piping/channels/bearing clearances will support it. After that, pressure shoots up with little additional flow.

IJ - I agree...the 7M oil system is stout. The only real improvement is getting rid of the stock cooler set-up and the way it dumps oil back to the pan. Full flow cooler system with a thermostat is the way to go.

 

[IJ.]

Been preaching the same thing for years now John......

Can't understand people that want to reinvent the wheel if something isn't broke don't fix it.......

If someone can show me a failure in a correctly built motor from Oil starvation due to flow restriction in the system I'll be happy to listen and lend a hand correctling it.

I don't manufacture parts or even sell car/engine parts anymore so I have no vested interest in turning a profit therefore I have nothing to gain here.

 

[suprarich]

I would trust a new pump in a new motor with the few simple mods mentioned for any motor up to 900 hp. Above that and spinning above 8k rpm, I would do a dry sump and run 85-95 psi with 3.4 to 4 ten thosand oil clearance. High horse power cars used in certain applications that have sustained g-force in one line (drag racing or circle track) could benifit from a better pick-up/oilpan design or the dry sump. There are external oil pressure regulators Aaron, used on dry sump system, but they only limit the max pressure. I have 85 psi at idle in my dragbike on a drysump system. I have wanted to make a drop in higher flow oil pump for the 7m for a long time, but never seam to have enough time.

 

[shaeff]

here's a quote that stuck with me for a few years now. word for word, i've always remembered it, and back when i was running thicker oil, this quote is the first thing that made me change my 1k mile old oil back to 10w30.

Pressure is resistance to flow.

since then, i've read many of JJ's and jdub's posts about oil, and have switched to using german castrol 0w30. i didn't have a huge drop in oil pressure either, as it's still within spec according to the book.

i've also upgraded to a full flow 180* t-stat, and an 11x8 cooler (both B&M), whilst removing the stock oil filter mount using a relocation kit. my pressure is just fine.

-shaeff